Journal of Toxicology and Environmental Health

Abstract In Michigan, United States of America, where Asian parasitoids were released to manage emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), we monitored four native parasitoids that also attack the invasive beetle – Atanycolus cappaerti Marsh and Strazanac, A. simplex (Cresson), and Spathius laflammei Provancher (all Hymenoptera: Braconidae), and Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae) – using yellow pan traps and tree dissections. Adult A. cappaerti, followed by A. simplex, had the broadest seasonal activity, S. laflammei was captured primarily in the first half of the growing season, and P. sulcata was restricted to mid-summer. Adult abundances of native species varied among years but, except for P. sulcata, were never significantly lower than the established Asian emerald ash borer larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius galinae Belokobylskij and Strazanac (Hymenoptera: Braconidae). Densities of emerald ash borer larvae parasitised by A. cappaerti or P. sulcata did not differ significantly from those of the two Asian species. Although adult A. simplex and S. laflammei were frequently captured, we did not confirm parasitisation of any emerald ash borer larvae by these two species, suggesting that they rarely attack emerald ash borer. We did not find any negative correlations between adult or immature parasitoid abundance of any parasitoid species, suggesting that any interspecific competition that may be occurring is negligible.

Abstract Trap colour can be an important consideration in detection programmes for arboreal and saproxylic beetles. Green and purple intercept traps are more attractive than black intercept traps to the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive species in North America. In four experiments, I tested three commercial multiple-funnel traps (green, purple, and black), baited with various lure blends, to determine the relative effects of trap colour on catches of other bark and woodboring beetles, and their associated predator species, in north–central Georgia, United States of America. I captured numerous species of Cerambycidae (Coleoptera) (n = 51), Curculionidae (Coleoptera) (n = 33), and associated predators (Coleoptera) (n = 22) across the four experiments. However, the majority of the species captured were either unaffected by trap colour or were caught in greater numbers in black and purple traps than in green traps. The two exceptions were the predators Enoclerus ichneumonus (Fabricius) (Coleoptera: Cleridae) and Pycnomerus sulcicollis LeConte (Coleoptera: Zopheridae), which were more abundant in green traps than in black traps. Purple traps performed better than black traps for the following species: Cnestus mutilatus (Blandford) (Coleoptera: Curculionidae), Cossonus corticola Say (Coleoptera: Curculionidae), Xylobiops basilaris (Say) (Coleoptera: Bostrichidae), Buprestis lineata Fabricius (Coleoptera: Buprestidae), and Namunaria guttulata (LeConte) (Coleoptera: Zopheridae).

Abstract Three Cannings brothers describe their intertwined but separate careers in Canadian biology: Rob as an entomologist, Syd as an entomologist and conservation biologist, and Dick as an ornithologist and politician. They emphasise the influence on their lives of the British Columbia’s Okanagan Valley where they grew up, the naturalist family in which they were raised, and the mentors who inspired them in their work. Bird study and nature interpretation in BC Parks were early enthusiasms and influences. Biological research, museum work, nature conservation, public education, and writing have dominated their careers. In Dick’s case, his public life has culminated in a decade of Canadian federal politics as a member of Parliament. This article is modified from the closing plenary address presented at Entomology 2022, the joint annual meeting of the Entomological Society of America, the Entomological Society of Canada, and the Entomological Society of British Columbia, in Vancouver, British Columbia, Canada, 16 November 2022. The presentation also acted as the 2022 Heritage Lecture of the Entomological Society of Canada.

Abstract We report the first observation of the Dorantes longtail, Thorybes dorantes (Stoll, 1790) (Lepidoptera: Hesperiidae), in Canada. On 16 April 2023, a single adult was observed on the northwest shore of Lake Ontario, in Toronto, Ontario, Canada. The observation represents a 1500- to 2000-km disjunction from the species’ nearest known populations in North America. After considering several scenarios that could explain the occurrence of the Dorantes longtail in Canada, the most likely explanation is that the observed individual came in on produce through the Ontario Food Terminal, Etobicoke, Ontario, providing another example of the constant pressure of species introductions to the region.

Abstract Rising atmospheric carbon dioxide (CO2) concentrations are a major driver of climate change, posing a significant challenge to global ecosystem functions. This challenge is compounded by the potential effects of elevated CO2 on forest pest insects like the eastern spruce budworm (Lepidoptera: Tortricidae), a major mortality agent in Canadian boreal forests. To better understand these impacts, this study investigates how elevated (1000 ppm) and ambient (469 ppm) CO2 concentrations affect budworm development across different life stages. In vitro experiments revealed that budworms exposed to the elevated CO2 concentration exhibited accelerated development, with increased larval weight gain from third to sixth instars, faster pupation and adult emergence, and earlier oviposition compared to those exposed to the ambient condition. However, elevated CO2 concentration led to reduced realised fecundity. These findings highlight the direct impact of elevated CO2 concentrations on budworm biology, with important implications for its role in forest ecosystems under climate change.

Abstract The radish fly, Delia planipalpis Linnaeus (Diptera: Anthomyiidae), is an emerging pest of broccoli and brassicaceous crops (Brassicaceae). The fly oviposits close to the stem of broccoli plants, and larvae feed within the stem and then pupate in the soil. Due to D. planipalpis’s recent appearance as a pest, no insecticides are registered for its management in Mexico. This study evaluated the efficacy of 13 synthetic and biological insecticides against different developmental stages through laboratory bioassays. Neonicotinoid-based products were highly toxic to the larvae, especially when applied via root irrigation, with thiamethoxam, clothianidin, and imidacloprid showing systemic activity. Thiamethoxam- and spinetoram-based products were also effective when applied to the stem oviposition site as a spray. A clothianidin-based product demonstrated moderate ovicidal activity, and bifenthrin had moderate residual activity against adult flies. A pyriproxyfen-based product effectively suppressed adult emergence. Products based on spirotetramat, neem (Meliaceae), and Tagetes (marigold) (Asteraceae) extracts and the microbial insecticide Bacillus thuringiensis var. israelensis (Bacillaceae) were ineffective against this pest. Spinosad and Sterneinema feltiae (Rhabditida: Steinernematidae) were not highly effective but could be used together with other control strategies in organic production. Neonicotinoids, spinetoram, and pyriproxyfen are promising options to validate in field trials for the management of D. planipalpis in broccoli.

Abstract Cytogenetic analyses have been widely used to understand evolutionary processes and to resolve taxonomic uncertainties in insects. In particular, the mapping of specific chromosomal regions can provide insights about the genome organisation and interspecific relationships. Considering the importance of this approach and the scarcity of chromosomal data in some groups of Hymenoptera, this study provides the first cytogenetic characterisation of the parasitoid wasp, Brachymeria (Pseudobrachymeria) vesparum Bouček, 1992 (Hymenoptera: Chalcididae). This species was characterised by 2n = 10 metacentric chromosomes. The heterochromatin was located at pericentromeric and terminal regions, being particularly conspicuous due to occupying a large part of chromosomes from pair 2. In addition, guanine–cytosine-rich blocks (GC+) were detected in the interstitial region of two chromosomal pairs. The data obtained were found to be useful for inferring the chromosomal rearrangements involved in speciation within Brachymeria, in addition to providing cytotaxonomic markers for further comparative cytogenetic studies.

Abstract Canadian entomology collections contain valuable biodiversity and ecological data. To be most accessible to those working outside of the collections, they need to be digitised. Multiple analyses of the digital database of the Odonata collection at the Royal British Columbia Museum (Victoria, British Columbia, Canada) were conducted. These analyses reveal that complete digital datasets can be used to explore questions of historical and current geographical distribution and species composition differences based on ecoprovince and elevation. The results of these analyses can be used directly in conservation and climate change impact mitigation decisions. These analyses are possible only because the Odonata collection has received concerted effort to digitise all specimen records. The full value of long-term historical insect biodiversity data can be accessed only once collections are digitised. Additional training and employment of collection management and curatorial staff is essential to optimise the use of abundant but underused Canadian biodiversity data.

Abstract Flower flies (Diptera: Syrphidae) are a ubiquitous family of true flies known for their hovering mating displays and pollinating behaviour. The flower fly genus Pterallastes Loew is represented by Pterallastes thoracicus Loew in North America, and its previously published range encompasses only the United States of America. Here, we report two new records for Canada and a previously overlooked historical record for the country. These data were used to generate an updated range map for the species, with additional iNaturalist records further expanding its known distribution in the United States of America. Finally, flower associations and natural history data for the species gathered from iNaturalist photos are discussed briefly.

Abstract Many population biology, ecology, and evolution experiments rely on the accuracy of the classification of individuals and the estimation of size population. The visual classification of vinegar flies, Drosophila melanogaster (Diptera: Drosophilidae), morphs is a laborious task usually performed by bench workers. Because of the size of the flies and the degree of precision needed to distinguish the morphological features on which the classification is based, the work is performed using a dissecting microscope. Here, we describe a method to automate the counting and identification of two types of vinegar flies, white and wild individuals. Our method is based on the image-recognition artificial intelligence (AI) tool, FlydAI (FlyDetector AI), which proved to correctly classify the flies when high-quality images were used, with a success rate of up to 100% in samples containing up to 200 individuals. This is a significant improvement with respect to preexisting approaches in terms of accuracy and specificity of the morphs detected. Although this tool is exclusively trained to routine lab tasks involving wild and white D. melanogaster, the AI can be easily trained to recognise different vinegar fly mutants and other types of insects of similar size, and its potential in other areas still needs to be explored.

Abstract Wild bees (Hymenoptera) that visit croplands rely on adjacent habitat to provide essential resources such as pollen, nectar, and nesting locations. This study compared wild bee assemblages on salt marshes and dykes, two coastal habitats proximal to cropland in Nova Scotia, Canada. We hypothesised that dykes would have a greater wild bee abundance and richness compared to salt marshes due to greater floral abundance and richness and nesting habitat availability. Wild bee richness and abundance differences between habitats were not significant. Most notably, Bombus (Latreille) and Megachildae (Latreille) bees were observed visiting a wind-pollinated salt marsh grass, Sporobolus michauxianus (Peterson and Saarela) (Poaceae). Several notable species were also observed, including the Committee on the Status of Endangered Wildlife in Canada species of concern, Bombus terricola (Kirby) (Hymenoptera: Apidae), and Lasioglossum taylorae (Gibbs) (Hymenoptera: Halictidae), a first Nova Scotia record. Floral abundance and richness were significantly greater in dyke habitats. These results contradict other studies that indicate a tight relationship between wild bees and floral abundance and richness. To help conserve these wild bees and their contributions to agriculture, more research is needed to understand how these species use salt marshes and dykes.

Abstract Insects experience variable temperature conditions in their natural environment, making constant temperature conditions in studies unrealistic. To address this, we investigated the effects of repeated short-term heat stress (STH) and short-term cold stress (STC) conditions on the pre-oviposition, oviposition, and post-oviposition periods, as well as on fecundity and egg viability of the parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae). We found that pre-oviposition periods were shortest under STH conditions and at the optimal temperature and longest under STC conditions. Conversely, oviposition and post-oviposition periods were longest at the optimal temperature. Oviposition periods were shortest under STH, whereas post-oviposition periods were shortest under both STH and STC conditions. Age-specific fecundity trends were triangular, and egg-viability trends were plateau-shaped at all temperatures. Females subjected to STH conditions experienced the highest oviposition peaks early in their adult life. Conversely, lifetime fecundity and longevity were highest at the optimal temperature, whereas egg viability was maximal under STH conditions. Regardless of the temperature they were maintained at, middle-aged females exhibited the highest fecundity and egg viability. Based on these results, despite reducing overall fecundity and longevity, STH conditions enhanced daily oviposition in females, with the peak occurring early in adult life. Additionally, both STH and STC conditions increased percentage egg viability in parthenium beetles.

Abstract The economic importance of insect pests in agricultural fields and the potential biological control by their natural enemies warrant foundational studies for the development of integrated pest management strategies. An insect survey was conducted in alfalfa (Fabaceae) seed production fields in southern Alberta, Canada, during the bud, flowering, and seed crop stages in 2020 and 2021. We examined the seasonal abundance of Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae), Lygus spp. Hahn (Hemiptera: Miridae), and 12 natural enemy taxa. We also examined the seasonal abundance, richness, and diversity of generalist predators and the seasonality of the two H. postica parasitoids, Bathyplectes curculionis (Thomson) (Hymenoptera: Ichneumonidae) and Oomyzus incertus (Ratzeburg) (Hymenoptera: Eulophidae). The seasonality of pests and natural enemies was inconsistent between years. Hypera postica larvae, B. curculionis, and O. incertus were present from mid-June to mid-August. However, we detected no correlations between H. postica larvae and its two parasitoids in either year. A number of generalist predators were correlated with A. lineolatus and Lygus spp. Further research is needed to understand the effects of environmental and biotic factors on the seasonality of pests and natural enemies in alfalfa seed production fields, and the insects’ trophic interactions.

Abstract Several broadleaf crops on the Canadian prairies suffer economic damage by Lygus bugs (Hemiptera: Miridae), populations of which are suppressed by parasitoids in the genus Peristenus (Hymenoptera: Braconidae). We used three different methods to assess levels of this parasitism for different instars of Lygus collected in southern Alberta, Canada. Screening Lygus for Peristenus DNA using a molecular polymerase chain reaction (PCR) method identified levels of parasitism ranging from 35 (second and third instars) to 47 (fifth instars) per cent. With dissection, parasitoids were recovered from 13 (second instars) to 44 (fifth instars) per cent of Lygus. For Lygus collected in the field and reared in the lab, Peristenus emerged from about 22 per cent of individuals. Our results show that use of PCR or dissection for fifth-instar larvae provides comparable estimates of parasitism. For earlier instars, PCR identifies levels of parasitism undetected using dissection – that is, 2.7-fold more for second instars in the present study. For the purposes of pest management and conservation biological control, dissection can provide adequate estimates of parasitism to inform a decision to reduce insecticides to protect Peristenus parasitoids.